.\" -*- nroff -*-
.\"
.\" copyright (C) 1997 Stephen Williams <steve@icarus.com>
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.TH poll_wait 9 "$Date:$" "Linux DDI" "Kernel Functions"
.\"
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.hlm 0
.na
.\" The name should be formatted this way for apropos to work
.SH NAME
poll_wait \- wait for selectable event to be ready
.\"
.\"
.SH SYNOPSIS
.B #include <linux/poll.h>
.PP
.BI "void poll_wait(struct\%wait_queue**" sync ", poll_table*" pt ")"
.HP
.\"
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.ad
.SH DESCRIPTION
This function is used in support of the poll device driver entry
point. The intent is for a device driver to put
.I sync
into the poll table immediately entering the device poll routine, then
returning a bit mask of events that are currently ready. The kernel
looks at the mask of events to see if something it needs is ready, and
suspends the process if not.
.PP
.nf
static unsigned int xxpoll(struct file*file, poll_table*pt)
{
    poll_wait(&data_in_sync, pt);
    if (data_in.cnt > 0) return POLLIN | POLLRDNORM;
    else return 0;
}
.fi
.PP
This example shows the basic use of
.BR poll_wait "(9)"
in a device driver poll function.
.SH AVAILABILITY
Linux kernel 2.1.34+
.SH "SEE ALSO"
.hlm 0
.na
.BR  intro "(9)"
.ad
.hlm 1
.SH AUTHOR
Stephen Williams <steve@icarus.com>
.SH BUGS
To early to say.
